Homopolyesters of 4,4'-biphenyldicarboxylic acid and certain aliphatic glycols are disclosed in the literature. Homopolyesters of 4,4'-biphenyldicarboxylic acid and ethylene glycol, 1,4-butanediol, and 1,6-hexanediol are disclosed by Meurisse et al., in the British Polymer Journal, Volume 13, page 57 (1981) (Table 1). Jackson and Morris include a review of homopolyesters from 4,4'-biphenyldicarboxylic acid and various aliphatic glycols in the Journal of Applied Polymer Science. Applied Polymer Symposia, 41, 307-326 (1985). Krigbaum et al., disclose relatively low molecular weight homopolyesters from 4,4'-biphenyldicarboxylic acid and various aliphatic glycols in the Journal of Applied Polymer Science, Polymer Letters Edition, 20, 109-115 (1982). Low molecular weight homopolyesters of 4,4'-biphenyldicarboxylic acid are also disclosed by Wanatabe et al., Macromolecules, 21(1), p. 278-280 (1988), and Krigbaum et al., Polymer, 24(10, p. 1299-1307 (1983). Jpn. Kokai Tokkyo Koho JP 61,236,821 [86,236,821](1986 ) also discloses low molecular weight polyesters from 4,4'-biphenyldicarboxylic acid and 1,4-butanediol prepared below their melting temperatures in a nonvolatile liquid. Polyesters of 1,6-hexanediol and 4,4'-biphenyldicarboxylic acid are disclosed in Kobunshi Ronbunshu, Vol. 44(12), 983-986 (December 1987) having limiting viscosity number of about 0.31.
U.S. Pat. No. 3,842,040 and U.S. Pat. No. 3,842,041 disclose the homopolyester of 4,4'-biphenyldicarboxylic acid and ethylene glycol.
German Offenlegungsschrift, DE 1935252, discloses polyesters of two aromatic dicarboxylic acids which include 4,4-biphenyldicarboxylic acid 10 to 50 mol %, 50 to 90 mol % of terephthalic acid and the two glycols ethylene glycol and 1,4-cyclohexane-dimethanol. Example 4 in this patent discloses a copolyester of 4,4'-biphenyldicarboxylic acid (BDA), ethylene glycol (EG), and 1,4-cyclohexanedimethanol (CD) of unknown composition having a melting point of about 300.degree.-305.degree. C. and a relatively low inherent viscosity (I.V.) of 0.5. High molecular weight copolyesters of BDA, EG, and CD are not specifically disclosed.
Japanese patent, Kokai Tokkyo Koho JP 57/198726 discloses copolyesters containing 25-80 mol % 4,4'-biphenyldicarboxylic acid with various aliphatic glycols and aromatic dicarboxylic acids.
Another patent which may be of interest is U.S. Pat. No. 2,976,266 which broadly discloses copolyesters prepared from 4,4'-biphenyldicarboxylic acid and certain aliphatic glycols. Copolyesters of BDA and EG but not CD are specifically disclosed in column 2, line 70 of U.S. Pat. No. 2,976,266 in a general listing along with other aliphatic glycols useful in this disclosed invention. High molecular weight copolyesters of BDA, EG, and CD are not specifically disclosed.
Another patent which may be of interest is U.S. Pat. No. 4,742,151 which discloses ultra-high-molecular weight polyesters prepared from aromatic dicarboxylic acids and alkylene glycols containing from 2 to 6 carbons having an intrinsic viscosity greater than 1.5. 4,4'-Biphenyldicarboxylic acid is disclosed in a list of dicarboxylic acids useful to the disclosed invention.
Heretofore, copolyesters of 4,4'-biphenyldicarboxylic acid, 1,4-cyclohexanedimethanol and ethylene glycol have been unknown.